Self-locking spring sash balance for tiltably-removable sash windows



March 25, 1969 G w. LOVE 3,434,237

SELF-LOCKING S PRING SASH BALANCE FOR TILTABLY-REMOVABLE SASH WINDOWS Filed April 12, 1967 Sheet of2 INVEN TOR 60900 mum z, .QFCEASEO 3. 6w m/zaiza mzarz 44 0 5744/0744. 57/404; ('0 1560 7025 ATTOR March 25, 1969 c. w. LOVE 3,434,237

SELF-LOCKING SPRING SASH BALANCE FOR TILTABLY-REMOVABLE] SASH WINDOWS Sheet Filed April 12, 1967 FIG.4

INVENTOR Gamay/141014; 0::[45/0 Ir Mmw'a w 10 v; 4M0

. ATTORNEY United States Patent 3,434,237 SELF-LOCKING SPRING SASH BALANCE FOR TILTABLY-REMOVABLE SASH WINDOWS Gordon W. Love, deceased, late of Birmingham, M1ch., by Mildred W. Love, 962 Abbey Road, Birmingham, Mich. 48008, and Stanley A. Simon, 1420 Holden Ave., Detroit, Mich. 48208, co-executors Filed Apr. 12, 1967, Ser. No. 630,791

Int. Cl. E0511 15/28 U.S. Cl. 49181 Claims ABSTRACT OF THE DISCLOSURE A self-locking spring sash balance for tiltably-removable sliding sash windows wherein the sash can only be swung inward for cleaning or removal, such swinging locking the spring sash balance in its attained position by a camming action of the spring-attached slide block against the channel sash guide. Accidental and unintended sash removal with consequent dropping and possible pane breakage is impeded by a bulbous wedge-shaped pivot element normally seated in a stifliy-yieldable C-shaped or U-shaped pivot block, the stiff arms of which normally resist yielding but which can be wedged apart by the bulbous element to intentionally remove the sash by a quick forceful pull.

Background of the invention Self-locking spring sash balances for removable sliding sash windows are known where at least one of the metal channel sash guides is spring-mounted to yield sidewise either by a sidewise push on the sash to dislodge one edge thereof from the non-yieldable sash guide whereupon the sash is removed bodily sidewise, or frontwise by a tilting and camming action of the sash upon the yieldable sash guide. In the former, the removal of the sash releases a locking element which in response to the pull of the sash balance spring digs into the sash guide and locks the spring in its attained position. This has the disadvantage of requiring complete removal of the sash in order to clean both sides of the pane, with the awkwardness of having to handle the weight of the entire sash and the danger of dropping it and breaking its pane. In the latter, the pivoting action performs a wedging effect between the slide block of the sash balance and the sash guide. This has the advantage of cleaning both sides of the pane without removing the sash, but involves the danger of accidental and unintended dislodgement and dropping of the sash either in an outward or inward direction.

Summary of the invention By the construction summarized above in the Abstract of Disclosure, the invention, by the use of a single-hump sash-balance-locking cam permits sash removal only in an inward direction. It ordinarily resists such removal yet readily permits tilting. Intended removal, however, can be effected by a quick and forceful pull upon the sash greatly in excess of the force required to tilt the sash.

In the drawings:

FIGURE 1 is a rear elevation of a double-hung tiltably-removable sliding sash window installation, equipped with the self-locking spring sash balance of the present invention;

FIGURE 2 is a fragmentary horizontal section, upon an enlarged scale, taken along the line 22 in FIGURE 1;

FIGURE 3 is a fragmentary vertical section upon an enlarged scale, taken along the broken line 3-3 in FIG- URE 1, showing the outer sash removed and the inner sash in process of removal, and showing the sash balance 3,434,237 Patented Mar. 25, 1969 in its locked position above and in its unlocked position below;

FIGURE 4 is a vertical section taken along the line 44 in FIGURE 3;

FIGURE 5 is a vertical section at right angles to that of FIGURE 4, taken along the line 5-5 in FIGURE 4;

FIGURE 6 is a vertical section through the locked sash balance after the sash has been removed, taken on the line 6-6 in FIGURE 3;

FIGURE 7 is a fragmentary rear view of a portion of one of the yieldable channel sash guides with one of the mounting springs mounted thereon; and

FIGURE 8 is a perspective view of one of the mounting springs of FIGURE 7 in its relaxed condition removed from its channel sash guide.

Referring to the drawings in detail, FIGURE 1 shows a rear view, looking from inside the room toward the window, of a tiltably-removable sliding sash window installation, generally designated 10, wherein the upper and lower tilting sashes 12 and 14 with panes 15 are equipped with pivoting self-locking removal-resisting but tiltably-removable spring sash balances 16 mounted in fixed and yieldable channel sash guides 18 and 20 respetively (FIG- URE 2) mounted in and secured to a conventional wooden window frame 22 having opposite vertical side members 24 and 26 to which the channel sash guides 18 and 20 are secured by screws 28 and 30 respectively. The channel sash guides 18 and 20 are of oppositely-facing but substantially identical construction, differing only in their means of mounting in that the yieldable sash guide 20 is additionally provided with longer guide screws 32, the heads of which are seated in conical-walled holes 34.

Each channel sash guide 18 and 20 (FIGURE 2) has double sash guide grooves 32 disposed in spaced parallel relationship for slidably receiving the upper and lower sashes 12 and 14 respectively. Each sash guide groove 32 has a back wall 34 bounded by a perpendicular side wall 36 on one side and a flared or oblique side wall 38 on the other. The back wall 34 is interrupted by an elongated vertical slot 40 and integral with a vertically-elongated spring sash balance housing 42 having opposite parallel side walls 44 and a rear wall 46, the latter being drilled at vertically-spaced intervals to receive the screws 28 in the case of the fixed channel sash guide 18 and the screws 30 in the case of the yieldable sash guide 20.

Yieldability is imparted to the yieldable sash guide 20 by double-armed wire springs 48 disposed at verticallyspaced intervals along the outside of each of the spring sash balance housing 42 in gripping engagement therewith. Each spring 48 (FIGURES 7 and 8) consists of a central lower bridge portion 50 from which two lower horizontal portions 52 extend perpendicularly. From the ends of the horizontal portions 52, vertical portions 54 extend upward to terminate in upper loops 56. From the loops 56, spring arms 58 extend downward, commencing in substantially vertical upper portions 60, continuing in inclined intermediate portions 62, and terminating in approximately vertical lower end portions 64.

In the relaxed and removed condition of each spring 48 (FIGURE 8), the vertical portions 54 converge upwardly toward one another so that the loops 56 are closer together than the lower horizontal portions 52 and the spring arms 58 diverge downwardly away from one another. When the springs 48 are installed, as shown in FIGURE 7, the vertical portions 54 and 60 and the loops 56 are wedged apart from one another by the spring housings 42 so that they firmly and frictionally grip the outer surfaces of the opposite side walls 44. As shown in FIGURE 2, the end portions 64 press against the vertical window frame side member 26 to resiliently urge the sash guide 20 against the adjacent side edges 66 of the sashes 12 and 14 (FIGURE 2).

Recessed as at 68 into the lower corners of the sashes 12 and 14 are two oppositely-facing pivot blocks or coupling lock actuators 70 of otherwise similar construction which serve as pivot bearings upon which the upper and lower sashes 12 and 14 pivot during tilting (FIGURES 2 to inclusive). Each pivot block 79 serves as the first component of a separable pivotal locking coupling, generally designated 72, and is of approximately C-shaped, U-shaped or horseshoe-shaped form and preferably formed from nylon or some other stifily resilient material. The pivot block or coupling lock actuator 79 (FIGURE 5) has a central bridge portion 73 positioned uppermost, and has parallel arms '74 extending downwardly toward a narrower gap 76 between their lower ends or entrance portions 78. Between the arms 74 is formed a verticallyelongated race-track-shaped slot or aperture 8-0, the lower end of which opens into the narrower gap 76. The opposite outer sides of the arms 74 and the lower ends 78 thereof are beveled as at 82 and 84 respectively to provide a camming action with the channel sash guide portions 38. Each pivot block 70 is drilled in several places to receive screws 86 by which it is held in its respective recess 68. The latter is of the same general C shape as the pivot block 70 but is widened or flared at its lower ends to permit sidewise yielding of the arms 74 when complete removal of the sash is desired.

Removably seated in each slot 80' or constantly aligned thereby with the gap 76 is the wedge-shaped lever arm or coupling arm 88 of a pivot cam lock member 90, which constitutes the second component of the separable pivotal locking coupling 72. The lever arm 88 is of bulbous or wedge-shaped longitudinal section (FIGURE 5) with an enlarged lower end 89 disposed adjacent the narrower gap 76 between the pivot block ends 78, which thus act as yieldable detents upon the lever arm or coupling arm 88, and with a smaller opposite upper end 91. Projecting horizontally from the upper end of the lever arm 88 and integral therewith is a pivot pin or shaft 92 which extends outwardly into a corresponding bore 94 (FIGURE 6) in a slide block or block carrier 96 and which has an integral annular cam flange 98 disposed intermediate its opposite ends. The cam flange 98 on its side facing the slide block 96 has a single bevelled radial cam hump or cam projection 100 which moves axially into and out of a corresponding radial bevelled cam notch or cam recess 102 extending downward from the bore 94 and axially inward from a counterbore 104 and having an annular abutment shoulder 105 between it and the bore 94. The counterbore 105 is of the same size and shape as the flange 98, so that when the pivot cam lock member 90 is rotated to permit the cam hump 100 to enter the cam notch 102 (FIGURE 4), the flange 98 lies flush with the slide block 96. When, however, the pivot cam lock member 90 is rotated 90 degrees from the position shown in FIGURE 4, the cam hump 100 is forced out of the cam notch 102 against the annular shoulder 105 between it and the bore 94 to move axially away from the slide block 96 into the locking position of FIGURE 6, wherein the block 96 and flange 98 are forced apart from one another into frictional locking engagement with the rear and front walls 46 and 32 respectively of the spring sash balance housing 42.

The slide block 96, as its name indicates, is an approximately rectangular vertically-elongated block and constitutes the third component of the separable pivotal locking coupling 72. The block 96 is also preferably of nylon and has at its upper end an integral upwardly-extending hollow spring attachment portion 106 (FIGURES 4 and 6) with a hole 108 into which the lower end hook 110 of an elongated sash balancing tension spring 112 is secured. The upper end loop 114 of the spring 112 is placed over the lower hook portion 116 of a spring anchorage member 118, the looped upper end portion of which is hooked over the upper edge of one of the side walls 44 of the spring housing portion 42 of the channel sash guide 20.

In the operation of the invention, let it first be assumed that the sashes 12 and 14 are detached from and are to be inserted in the window frame 22. To insert either of the sashes 12 or 14, for example, the lower sash 14 (FIGURE 3) is aimed at the slide blocks 96 in such a manner that the gaps 76 in the pivot blocks are aligned with the smaller ends 91 of the lever arms or coupling arms 88, whereupon a forward push upon the sash 14 causes the wedge-shaped lever arms 88 to push apart the ends 78 of the pivot blocks 70 and enter the elongated slots 80, the ends 78 then moving inward toward one another behind the lever arms 88, by reason of their resilience, to narrow the gaps 76 and releasably lock the enlarged ends 89 of the lever arms 88 in their respective slots 80. The sash 14 is then swung upward into the plane of the window frame 22, thereby rotating the lever arms 88 and the cam flanges 98, causing the cam humps 100 to move into their respective notches 102 from the position of FIGURE 6 to that of FIGURE 4. As a result, the cam flange 98 disengages itself from locking frictional engagement with the outer wall 32 of the spring housing 42, releasing the tension springs 112 and permitting them to resume their sash-balancing action.

To tilt either of the sashes 12 or 14, for example the lower sash 14, the user lowers the sash 14 to a convenient location, such as that shown in dotted lines in FIGURE 3, and tilts the sash inward around the pivot shaft 92 as pivot axes. The user can conveniently clean both sides of the pane 15. Ordinarily, bodily removal of the sash 12 or 14 is not required, and the sash can then be swung upward into its vertical position in the plane of its particular sash guide 20, with the beveled surfaces 82 of the pivot blocks 70 engaging the inclined cam surfaces 38 of the sash guides 18 and 20 to force the movable sash guide 20 laterally away from the fixed sash guide 18 and permit the sash 14 to enter the space between them (FIGURE 2).

During the pivoting procedure, the larger or bulbous ends 89 of the wedge-shaped lever arms 88 prevent the sash 14 from accidentally and unintentionally disengaging itself from the slots by reason of the detent action of the entrance portions 78 on the opposite sides of the restricted gaps 76 through which they must otherwise pass. Should the user, however, desire to remove the sash 12 or 14 completely, such as to replace a broken pane 15, he gives a sudden and forceful jerk or pull to the sash 12 or 14. This action causes the enlarged ends 89 of the lever arms 88 to widen and force their way through the gaps 76 as they push apart the ends 78 of the arms 74 of the pivot blocks 70. The sash 12 or 14, as the case may be, can only be removed in this manner. Meanwhile, the rotation of each pivot cam lock member by its lever arm 88, in response to the tilting of the sash 12 or 14 moves the cam hump out of its bevelled notch 102 and against the annular shoulder 105, thereby in effect thickening the slide block 96 to frictionally wedge or jam it inside the spring sash balance housing 42, as explained above.

What is claimed is:

1. A self-locking pivoting spring sash balance construction for a tiltably-removable sliding window sash adapted to be installed in a window frame, said sash balance comprising a pair of elongated vertical sash guides adapted to be mounted on opposite sides of the window frame,

at least one of said sash guides being adapted to be resiliently mounted on one side of the window frame,

each of said sash guides including a hollow vertical sash balance housing having a rear wall and having a front wall with an elongated vertical opening therein,

a sash balancing spring mounted in each housing and anchored at one end thereto,

a slide member slidably mounted in each housing and connected to the opposite end of each said spring,

said slide member having a bore aligned with the opening in said front wall and having an abutment portion transverse to said bore,

a pivot cam lock rotatably mounted in each slide member bore and projecting through said opening and having a coupling portion thereon disposed externally of said openint said slide member and said pivot cam lock member having interengaging cam portions thereon responsive to the rotation of said pivot cam lock member by tilting of the sash to move said members axially relatively to one another into locking engagement with said front and rear walls, and a coupling lock actuator adapted to be secured to each of the opposite sides of the sash in aligned separable engagement with one of said pivot cam lock members,

said coupling lock actuator being of stifiiy resilient material and having an aperture therein configured to fit said coupling portion of said pivot cam lock member and a gap narrower than said aperture and said coupling portion leading outward from said aperture and having detent portions yieldable in response to the forcible insertion and withdrawal of said coupling portion from said aperture.

2. A self-locl ing pivoting spring sash balance construction, according to claim 1, wherein said coupling portion of said pivot cam lock member has an enlargement thereon exceeding the width of said gap whereby to spring apart the entrance portions of said coupling look actuator in response to insertion or removal of said coupling portion from said aperture through said gap.

3. A self-locking pivoting spring sash balance construction, according to claim 2, wherein said coupling portion is of tapered configuration, and wherein said enlargement constitutes the widest part of said coupling portion.

4. A self-locking pivoting spring sash balance construction, according to claim 1, wherein said coupling lock actuator is of approximately U-shaped configuration, and wherein said aperture is of elongated outline.

5. A self-locking pivoting spring sash balance construction, according to claim 1, wherein said resilientlymounted sash guide has bifurcated springs thereon with attachment portions grippingly engaging said sash balance housing and with spring anms projecting obliquely therefrom.

References Cited UNITED STATES PATENTS 3,055,062 9/1962 Peters et al. 49-174 3,055,063 9/1962 Peters 49-181 X 3,108,335 10/1963 Osten 49-181 X 3,118,190 1/1'964 Love 49-181 X 3,184,784 5/1965 Peters 49-181 X DENNIS L. TAYLOR, Primary Examiner.

US. Cl. X.R. 16-197 

